Inside STG’s galley cart testing for floor path marking

When it comes to aircraft safety, every single part of the cabin must be meticulously tested to ensure each detail is fit for purpose. Floor path marking is a key safety feature in the cabin as it guides passengers to exits during emergencies.

At STG, we have specific testing processes in place, and our custom-built galley cart testing process is one of the most rigorous assessments these systems undergo before they ever reach the market.

STG’s galley cart testing rig isn’t something off the shelf. It was custom designed by the company, incorporating a genuine aircraft galley cart.

We spoke to Tracy Vyas-Middlecoat, our Research and Development Scientist, about the process of testing.

Why galley cart testing matters

Galley cart testing is a form of accelerated life testing designed to replicate decades of in-service wear and tear in just a few days. The test simulates the repeated impact of fully loaded galley carts, often full of food and drink that the cabin crew roll down aircraft aisles, passing over floor path marking tracks thousands of times.

Tracy said:

“It’s the best way to see how our systems hold up under realistic, long-term use. A fully loaded cart weighs around 150 kilograms which we run for 20,000 cycles - the equivalent to about 35 years of service. The process allows us to spot weaknesses long before they could become an in-service issue.”

The primary goal is to detect cracking or other structural weaknesses over the course of the test. The team monitors the samples every 1,000 cycles to keep track of its durability. If cracks appeared before 1,000 cycles it would show significant robustness issues, and changes would need to be made.

Different profile shapes and widths behave differently under pressure, so every new design or material variant must be tested in this way. This was the case when STG moved from its traditional virgin polycarbonate to an eco-friendly alternative material with the same profile. It still underwent full durability testing.

How the process works

The process starts with preparing a test track using either carpet or non-textile flooring, cut to match the installation environment. The floor path marking samples are fitted exactly where the trolley’s wheels will pass, secured with the same adhesive used in actual installations.

Then the galley cart, mounted on a custom-built pneumatic track system, is set into motion. Over three days, it moves back and forth continuously, stopping only for inspections at different stages. On occasion, the cart has been left running far beyond the intended cycle count. Tracy said: “We’ve accidentally forgotten about it before and found it’s done 70,000 cycles, and sometimes, no cracks!”

Metrics and pass/fail criteria

The key measurement is simply identifying when the visible cracking occurs. STG considers a product robust if no cracking occurs before the completion of the test, providing an acceptable in-service lifespan.

The test is so integral to their design process that it also serves as a development tool. In one recent R&D project for a new profile, early prototypes cracked within 2,000 cycles due to a curved edge design. The insight led to design changes before significant time and financial investment.

Beyond Galley Cart Testing

 While galley cart testing focuses on durability, STG runs additional tests to ensure overall performance. These include impact testing which simulates the effect of heavy objects (like a suitcase) falling onto the track from overhead bins. Flammability testing is also performed on every batch of product to meet stringent aviation standards, with in-house certification capability. Finally, fluid ingress testing is performed to exposed sealed and unsealed samples to everything from jet fuel to red wine, ensuring safety even if appearance is compromised.

These layered tests are there to catch issues that could have otherwise gone unnoticed, and ensure full reliability of each product that goes out the door.

From its realistic simulation of service life to its role in refining designs before they reach the market, galley cart testing is more than a box-ticking exercise. It’s a cornerstone of STG’s commitment to delivering floor path marking systems that perform flawlessly, not just on day one, but for decades of flights to come.